Sentences with phrase «stable isotopic»

The stable isotopic composition of the carbon in carbon dioxide over the last 24,000 years illuminates past carbon cycle behavior.

«Because we extracted high - resolution stable isotopic profiles from these shells, we were able to match them to active spells and breaks in the monsoon,» Thirumalai said.

The methane stable isotopic signature indicated production through acetoclastic methanogenesis, but gene signatures from acetoclastic and hydrogenotrophic methanogenic Archaea were detected in both polygonal and runnel ponds.

The methanogenic pathways and C age were investigated through stable isotopic signatures and radiocarbon dating of dissolved and bubbling GHG.

With regard to breeding status, solitary females had higher δ15N values and smaller variance in their stable isotopic values than females with cubs, suggesting that solitary females were more selective and prey on higher trophic level species (i.e. seals).

On the AAE 2013 - 2014 we undertook to map the stable isotopic signatures in seals to investigate whether there has been a change in diet over time.

«Because we extracted high - resolution stable isotopic profiles from these shells, we were able to match them to active spells and breaks in the monsoon,» Thirumalai said.

Stable isotopic compositions — variants of particular chemical elements — of such remains, recovered from soil and lake sediment, may help us better understand climate change over a long span of time.

Not exact matches

Ecologists can now combine classic stable istopic tracers with any number of parameters, like temperature range, salinity, or newly discovered isotopic tracers.

By using isotopic tracers called stable isotopes, researchers showed that seabirds feeding in areas rich in sulfate (a chemical that is an important food for sulfate - reducing bacteria that help break down organic matter) had high levels of mercury.

But we found the isotopic composition of the deep water was similar to that of modern rainfall, which means the system in the Sydney Basin has been relatively stable for thousands of years.

The information about oxygen concentration comes from the isotopic composition of carbon or rather from the ratio between the stable carbon isotopes 12C and 13C.

I joined the team and undertook isotopic work using oxygen, nitrogen and carbon stable isotopes to assess his geographical origin and also his diet.

Bell L.S., Lee - Thorp J.A. & Dobney K. (2006) Mapping human movement using stable oxygen isotopic mass spectrometry: potential application to forensic science.

It is possible to reconstruct past precipitation changes by measuring the stable hydrogen isotopic composition in terrestrial plant waxes because rainfall is the primary source of hydrogen stored in plant material.

Conservative tracer studies using stable oxygen isotopic data from 307 sites show that while the entire surface of this area receives abundant freshwater from meteoric sources, freshwater from sea ice melt is most closely linked to the areas of carbonate mineral undersaturation.

Stable isotope geochemistry is the study of how physical and chemical processes can cause isotopes — atoms of an element with different numbers of neutrons — to separate (called isotopic fractionation).

The isotopic data evaluated above is derived from the fractionation of the naturally occuring stable isotopes of Carbon, 12 and 13.

It is appropriate as this point to add that if Bolin & Eriksson's conditions in the last paragraph were true, carbonated beer (Bohren, 1987) and soda «pop» as we know it would be an impossibility with their «buffer» factor (see below); rain and fresh water would not show the observed equilibrium pH of 5.7 (Krauskopf, 1979); and experiments would not had shown complete isotopic equilibrium between CO2 and water in just hours, which in turn is the prerequisite for routine stable isotope analysis involving CO2 (Gonfiantini, 1981).

«THE stable carbon isotopic (13C / 12C) record of twentieth - century tree rings has been examined1 - 3 for evidence of the effects of the input of isotopically lighter fossil fuel CO2 (δ 13C ~ -25 ‰ relative to the primary PDB standard4), since the onset of major fossil fuel combustion during the mid-nineteenth century, on the 13C / 12C ratio of atmospheric CO2 (δ 13C ~ -7 ‰), which is assimilated by trees by photosynthesis.

Using isotopic and chemical tracers, the researchers estimate that the CO2 had been mineralized into benign and stable carbonate minerals in the space of just two years.

The classic paleothermometer is the stable - isotopic composition of water in the ice core (10).

Experience includes but is not limited to core analysis, X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Scanning Electron Microscopy (SEM), petrography, stable and radiogenic isotopic analysis, and / or data analysis.